Hibernation mostly takes place in natural or artificial underground sites. Nursery colonies use buildings in central and eastern Europe and underground sites in the south of the continent. Tree cavities or bat boxes are occasionally used. Nursery colonies may be numerous, numbering hundreds of bats or more, while in summer males roost alone or in small groups. Myotis myotis often hibernate alone but groups of up to several hundred bats have been recorded (reviewed in Zahn et al. in press).

The species often hunts in open areas or the forest, provided trees are sufficiently spaced out and no significant undergrowth is present. It flies low over the ground where prey is detected by passive listening thanks to the rustling sound they produce, and gleaned from the ground. Carabid beetles are the species’ staple food, especially in central Europe, while they are less vital in the south, where other large beetles, arachnids, orthopterans, and centipedes may be eaten (reviewed in Zahn et al. in press).

This is a regional migratory bat that moves seasonally from hibernacula to nursery roosts, with movements that are frequently > 100 km and up to 436 km (Hutterer et al. 2005).

In Europe, the Greater Mouse-eared Bat occurs in the western, central and southern parts of the continent. Few records regard southern England and southern Sweden. Its range, eastwards, includes eastern Poland, western Belarus (Bialowieza), western Ukraine and the Black Sea. It occurs in the Balearic Islands and Sicily; bone remains are known for the Azores, where no live bat was ever recorded (Zahn et al. in press). The range of altitudes where this species can be found varies between 0 and 1,800 m asl. The AOO and EOO have not been estimated, but based on the available locality records, they are expected to greatly exceed the threshold for a threatened category.

Out of Europe, it is known for part of Asia Minor and the Levant, including Türkiye, Syria, Lebanon and Israel (Zahn et al. in press).

Myotis myotis is protected by national legislation in most range states, as well as by the EUROBATS Agreement and Bern Convention. It is listed under Annexes II and IV of the EU Habitats and Species Directive, so its protection in the EU requires the designation of Special Areas of Conservation. According to this Directive, 3525 Natura 2000 Sites have been designated to protect this species. Reporting done under Article 17 of the 92/43/EEC Habitats directive shows that in 2013-2018 the species' conservation status was ‘unfavourable-inadequate’ in all European biogeographical regions, with contrasting patterns in the different countries (https://nature-art17.eionet.europa.eu/). No significant evidence is provided about declining trends on the European scale. The survival of this species hinges on the protection and preservation of its underground roosting sites, as well as the buildings it uses during summer across much of its range. Furthermore, the preservation of heterogeneous agricultural landscapes and open spaces, such as pastureland, is crucial in providing vital foraging habitat for this species.